Koellner F.,GGL Geophysik und Geotechnik Leipzig GmbH |
Pomponi E.,University of Leipzig |
Sens-Schonfelder C.,German Research Center for Geosciences |
Schuck A.,GGL Geophysik und Geotechnik Leipzig GmbH
Near Surface Geoscience 2013 | Year: 2013
The present study introduces combined active and passive seismic investigations on a railroad embankment that is constructed on a soft layer of peat clays. This type of sediments causes the embankment to be in a dynamic movement whenever trains are passing. As long term consequence the stability of the embankment is affected. Based on the concept of seismic interferometry temporal changes in the medium due to the heavy dynamic force load induced by the train can be identified. Furthermore, velocity information of travling body waves that have been retrieved by cross-correlating the signals of train passages are compared to results from seismic crosshole measurements.
Sens-Schonfelder C.,Helmholtz Center Potsdam |
Niederleithinger E.,BAM Federal Institute of Materials Research and Testing |
Gassenmeier M.,Helmholtz Center Potsdam |
Thiemann K.,K UTEC AG Salt Technologies |
Kollner F.,GGL Geophysik und Geotechnik Leipzig GmbH
7th European Workshop on Structural Health Monitoring, EWSHM 2014 - 2nd European Conference of the Prognostics and Health Management (PHM) Society | Year: 2014
Utilization of coherent phase information in complex wave fields forms the basis of interferometric time series analysis. The concept is known since decades, but until about 15 years ago there have been no practical implementations. Meanwhile seismic interferometry is used in a wide range from investigations of the earth's deep crust to engineering applications. Focused on monitoring and imaging the MIIC (Monitoring and Imaging based on Interferometric Concepts) project as part of the German GeoTechnologien program has contributed to this development. Special attention was given to the transfer of methodology to different length scales that range from centimeters, in laboratory applications, over geotechnical scales to even kilometers in seismological applications. General purpose methods and open source software was developed, which can be used on all scales. The core of the MIIC software is a Python library organized in different modules for various processing tasks. A graphical user interface facilitates the creation of processing routines by visualizing connections and dependencies of variables and by checking the consistency of data types. Example applications have included carbon sequestration, salt mine and railroad embankment monitoring as well as imaging changes in concrete constructions. Copyright © Inria (2014).
Byrdina S.,University of Savoy |
Rucker C.,TU Berlin |
Zimmer M.,Helmholtz Center Potsdam |
Friedel S.,COMSOL Multiphysics GmbH |
Serfling U.,GGL Geophysik und Geotechnik Leipzig GmbH
Journal of Volcanology and Geothermal Research | Year: 2012
This paper analyzes simultaneous self-potential and gas temperature variations recorded at Merapi volcano in spring 2011, the dry season shortly after the volcanic crisis 2001. Temporal variations of fumarole gas temperature show characteristic quasi periodic signals at scales 1-8. h and amplitudes up to ten degrees. We propose a simple graphical technique combining a wavelet scalogram and a cross-correlation analysis to demonstrate that the variations of gas temperature are systematically preceded by self-potential variations at the same scales. The influence of meteorological variations on these correlated signals can be ruled out. Rather, we suggest them to be related to the magma degassing in the upper conduits of the volcano. We discuss a semi-qualitative model to explain this correlation and the observed phase shift of about two hours. © 2011 Elsevier B.V.
Sandig C.,Helmholtz Center for Environmental Research |
Sauer U.,Helmholtz Center for Environmental Research |
Brauer K.,Helmholtz Center for Environmental Research |
Serfling U.,GGL Geophysik und Geotechnik Leipzig GmbH |
Schutze C.,Helmholtz Center for Environmental Research
Environmental Earth Sciences | Year: 2014
Our study at this natural analog site contributes to the evaluation of methods within a hierarchical monitoring concept suited for the control of CO2 degassing. It supports the development of an effective monitoring concept for geological CO2 storage sites-carbon capture and storage as one of the pillars of the European climate change efforts. This study presents results of comprehensive investigations along a 500-m long profile within the Hartoušov (Czech Republic) natural CO2 degassing site and gives structural information about the subsurface and interaction processes in relation to parameters measured. Measurements of CO2 concentrations and investigation of the subsurface using electrical resistivity tomography and self-potential methods provide information about subsurface properties. For their successful application it is necessary to take seasonal variations (e.g., soil moisture, temperature, meteorological conditions) into consideration due to their influence on these parameters. Locations of high CO2 concentration in shallow depths are related to positive self-potential anomalies, low soil moistures and high resistivity distributions, as well as high δ13C values and increased radon concentrations. CO2 ascends from deep geological sources via preferential pathways and accumulates in coarser sediments. Repetition of measurements (which includes the effects of seasonal variations) revealed similar trends and allows us to identify a clear, prominent zone of anomalous values. Coarser unconsolidated sedimentary layers are beneficial for the accumulation of CO2 gas. The distribution of such shallow geological structures needs to be considered as a significant environmental risk potential whenever sudden degassing of large gas volumes occurs. © 2014 Springer-Verlag Berlin Heidelberg.
The application of innovative geophysical methods to the site investigation of flood reservoirs and dams - Case studies [Der Einsatz von innovativen geophysikalischen Methoden bei der Erkundung von Hochwasserrückhaltebecken und Talsperren - Fallbeispiele aus der Praxis]
Hohlfeld T.,GGL Geophysik und Geotechnik Leipzig GmbH |
Dorrer T.,GGL Geophysik und Geotechnik Leipzig GmbH |
Serfling U.,GGL Geophysik und Geotechnik Leipzig GmbH
WasserWirtschaft | Year: 2013
Beside single geotechnical drillings also suitable geophysical methods should be used for the detailed investigation of flood reservoirs and dams. Based on two case studies the benefits of using geophysical methods for solving geotechnical problems are shown in this paper. For each example, an applied geophysical method and its suitability for a specific project will be explained.